1. Field of the Invention
This invention relates to mine vehicles and more particularly to a mine car utilized for the loading, transporting and unloading of mine materials.
2. Description of the Prior Art
Vehicles for use in mine shafts are characteristically constructed with a low profile to operate in the constraints of the mine shaft. The most commonly used vehicles are self propelled rubber tired vehicles having an integral scoop attached thereto. Typically mine vehicles which function to load, transport and unload mine materials are constructed as traction vehicles having the scoop supported at one end of the vehicle. The integral scoop is usually supported from the vehicle frame and is raised or lowered as required during operation. While the scoop can be raised or lowered as desired its longitudinal axis cannot be moved from side to side.
During a typical operation the vehicle is driven into the mine shaft to a point where a particular material is piled. The scoop is then lowered to ground level by hydraulic arms and the traction vehicle then forces the scoop forward to collect the material. When the scoop is loaded it is raised to a higher position and the mine vehicle is driven from the mine to unload the material. U.S. Pat. Nos. 3,226,857, 3,545,634 and 3,777,915 represent self powered mine vehicles which are exemplary of this type construction.
Many problems are associated with mine vehicles of the type described above due to the restricted space and heavy loads encountered in the scoop. Since the scoop is supported from the mine car it functions as a lever to transmit motions imparted to the mine vehicle, for example, due to rough road surfaces. With the scoops rigidly attached to the frame, as the mine vehicle travels through the shaft, turbulence of the load is caused which either results in the loss of the mined material, within the shaft, or necessitates slower operation of the vehicle.
Also since the mine cars are of a low profile the raising and lowering of the scoop must be accomplished by apparatus which does not extend in height much above the scoop, which requires relatively heavy structural members. The self propelled vehicle must also be constructed with a suffficient counter weight to offset the load carried in the vehicle. As the load becomes greater the effect of the counter weight is decreased, increasing likely movement of the scoop during operation.